Planning For Quality Welds

This article provides the way to plan and control your welding operations and how to ensure that welds will have “zero defects” and establish practical methods which achieve that result. 

Welding on its own is a complex, interesting science. Planning and then managing to the plan, if done completely, will ultimately bring the desired improvements. Welding is not solely an

art but a combination of science and art. Improvements in welding generally do not take a lot of capital investment. We need more knowledge in the areas of ‘The basics in welding’.

While you might think we know everything there is to know about the most widely used welding processes and materials that simply isn’t the case, industry needs “more practical

application data relative to welding”.

We need to be able to transfer current welding knowledge to the factory floor. More trained professionals and dissemination of knowledge are needed [1].

Creating a good weld may not be easy. Quality of workmanship and compliance to drawing and contract criteria are vital elements in the fabrication of safe, reliable and trustworthy

weldments [2].

The commitment of each company begins and ends with the management. The fabrication contractor shall be responsible for performing all required inspections relating to fabrication

and welding unless specified otherwise within the contract documents [3].

Sharing our experiences on why some companies succeed when others fail to improve their weld quality and productivity. Presenting a few final thoughts on keys to success and your

new culture [4].

1. Welding 

Welding is a critical technique for the joining of materials in the nation’s major manufacturing industries. It is a big challenge for industry to include welding technology in its production

with the number of new problems and failures that occurring in the beginning, which needed to be resolved Fig.1. 

Over its 100 year history, welding has become one of the most essential technical skills in manufacturing and fabrication. Because of the diversity of possible applications and the fundamental utility of the process, welding is an important element in ship welding, automobile manufacturing and repair, aerospace applications, engineering and infrastructure. This is understandable, since welding is used not only for manufacture of almost everything made of metal, but it is the maintenance tool which keeps our railroads, truck fleets, steel mills, power plants, waterworks, refineries and other vital national functions on the go because of welding strength. The welding technology advanced and strengthened its position to be the leading method for metal joining in globally.

There are a lot of challenges to overcome in moving forward. Welding will be associated with the products that offer performance and endurance and that can be serviced. Competitive pressures will drive fabricated products towards having zero defects and lifetime reparability. Although every product has some defects or discontinuities, the challenge is to know the level that is acceptable for desired performance of the product. Welded products approach zero defects, eliminating the need for repairs and re-handling and ensuring cost effective.

2. Importance of Weld Quality

Certain industries that involve welding of their products have very strict quality standards to ensure the production of sound welds. Many others however, do not. They simply weld and

unless one of their products fails they don't pay special attention to welding procedures, detailed inspection of welds or testing the skill (performance) of their welders. One of the

biggest problems in welding is that it may take only one failure for something catastrophic to occur. Unfortunately, in some cases these, these failures result significant monetary losses,

injuries and/or death. 

Failures will happen; we cannot guarantee that weldments and welded connections will never fail. What we can do is make sure we do

our due diligence when setting up and managing welding operations. Welds are always potential points of weakness in structure and

will always contain imperfections to some extent. Failures often occur around welds, but not necessarily related to poor welding practice.

If a weldment is to have the required reliability throughout its life, it must have a sufficient level of quality or fitness for purpose Fig.2.

Fig.2.               

Quality includes design considerations, which means that each weldment should be:

1. Adequately designed to meet the intended service for the required life

2. Fabricated with specified materials and in accordance with the design concepts

3. Operated and maintained properly.

Defect

A weld that does not meet any or all of the specific requirements of a particular specification or code is considered defective weld. In the correct sense of the word, a defect is a

rejectable discontinuity or a flaw of rejectable nature. Certain flaws acceptable in one type of product and need not be of acceptablenature in another product. A defect is definitely

a discontinuity but a discontinuity need not necessarily be a defect.

General Reasons for Defects

The importance of weld quality is increasingly felt as we go ahead with the fabrication of sophisticated products using higher strength materials combined with critical design

consideration. However, defects are likely to be present in materials produced at economic cost. Defects are generally introduced because of:

• lack of know- how and experience

• welding process characteristics

• base metal composition

• defective welding filler metals

• joint design

• welding environment (wind, fit up, temperature, etc.)

Type of Defects 

Defects in weldments in general can be classified as follows: 

• Defects involving inadequate bonding - lack of fusion, incomplete penetration;

• Foreign inclusion – slag, tungsten, oxide films;

• Geometric defects – undercut, excessive reinforcement, burn through or excessive penetration, distortion, improper weld profile;

• Metallurgical defects – cracks, gas porosity, arc strikes Fig.3.                                                                                                               

Fig.3. Defective Weld          

Defects Acceptance Level

Defect acceptance levels are included in certain specifications - especially application specifications. Some specifications contain defect acceptance tolerances which are stricter

than others, depending on the criticality rating of the structure or application to which the specification applies.

Evaluation 

Weld quality is verified by non destructive examination. The acceptance standards for the welds are generally related to the method of non destructive examination. All deviations

are evaluated and the acceptance or rejection of a weld is usually based on well defined conditions.

4. Welders 

The quality of the resulting weld is heavily dependent upon the skill of the individual welder. The quality will be there if the welders are properly informed. Welders should be made

part of the quality assessment team. Welders use all types of welding equipment in a variety of positions such as flat, vertical, horizontal and overhead. They may perform manual

welding, in which the work is entirely controlled by the welder or semi-automatic welding, in which the welder uses machinery, such as a wire feeder, to perform welding tasks. 

They generally plan work from drawings or specification or by analyzing damaged metal, using their knowledge of welding and metal. They select and setup

welding equipment and may also examine welds to insure that they meet the standards or specifications. Some welders have more limited duties. They

perform routine production work that has already been planned and laid out Fig.4. 

Fig.4. Performing Welding  

The welding system is built on the fundamental beliefs those welders:

1. want to do a good job everyday

2. are proud of their work

3. want to improve and are open to learning

4. need to be supported

5. want to be responsible for the quality of their own work.

6. need some feedback on performance and coaching to improve

If top management hold and practice these beliefs about welders, then your company will be successful [6]. Many welders are still taught by other welders. Some are trained in

technical vocational institutes and some learn on their own through trial and error.

Welders skill gap issue is a global concern. The welding industry is very much aware of the need to improve trainee skills. Still, the challenge we must overcome is the lack of

young people choosing to embrace a career in welding and the welding field. “The welder’s environment must become more attractive” [7].

Without skillful welders, welding wouldn’t be able to win ground from other repair methods. We can conclude that

eyesight and the ability to distinguish between liquid slag and liquid metal against a very bright electric arc and a dark image of the previous bead and welding groove is 

important in the welding process control.

Fig.6. Excessive Reinforcement Underfill 

Improve Worker Morale

Inexperienced or poorly motivated workers definitely discourage and tend to drag down the productivity of even the most highly qualified welders and fitters. Sometimes the foremen

end up doing field work more than that should with the result their assigned duties of supervision is neglected. Even the introduction of new equipment can be demoralizing if the work

force is ill trained or poorly motivated to use it properly. Finally there is a little financial incentive for experienced workers to apply themselves when they are paid at nearly the

reasonable rate. The management to routinely review prices with various vendors, suppliers every 6 months to assure the lower cost for materials; implement continuous training

programs; try to improve worker morale; review product design to make it easier to fabricate and try adding a fit up inspection prior to welding to minimize rework expenses.

A large percentage of welders were not trained by a qualified welding instructor. And a ‘self taught’ welder can perfect a lot of bad welding habits in a few years. Finally, welders and

welding technicians need to be properly schooled in the areas of welding in which they will be involved. They need to be spend adequate time in skill training and skill maintenance

areas, with training provided by knowledgeable instructors.

8. How to Achieve Successful Welds

The process of producing a quality weld begins with having accurate manufacturing drawings, identifying the correct welding procedure and using skilled welders and welding

operators. The following are recommendations to complete a successful weld: [19] 

1. Audit the shop process: You need to look at the whole production process from the moment the plate comes in until the part leaves the shop.

2. Ensure use of trained welders: Be realistic in your expectations. Don't just tell your welders what to do, show them how to do it.

3. Reduce or eliminate welding variables: Check that the plate or pipe is clean prior to welding. If possible, make sure the weld can be made in a comfortable position for the welder. If not, consider using a welding positioner Fig.7. Eliminate poor fit-up between the plates; any gaps or alignment problems will cost difficulties.

4. Examine the workplace and environment: A comfortable welder is a more productive welder, and a less fatigued welder produces better welds. Weather factors may influence the welders fatigue.

Fig.7. Welding Positioner          

Take a moment to look at welder fatigue and at each welder’s workplace. Determine if it is a healthy environment by asking the following questions:

• Is it a clean workplace? 

• Is there good lighting so weld defects can be easily spotted?

• Is there adequate ventilation?

• Is there a fume control system and is it working?

Look at the welder’s physical position when welding. You may find the benches are too high or too low. 

1. Practice safety: If the company takes the time to train it's welders about safe practices and the value of safety, they will begin to make safe practices a habit. Safety should always come first. Make sure the welder is provided the proper protective clothing and welding helmets Fig.8.

2. Use approved plans and drawings: The use of quality drawings that are correct before the job is started will save costly revisions later.

3. Check critical dimensions: The cost of rework on the job is extremely high. Checking and rechecking of critical dimensions help to minimize the unneeded expense of rework.

4. Review appropriate welding procedures: Welding procedures have been established to meet the code and safety requirements. These procedures are also established to confirm the work is being performed in the most cost effective way.

5. Verify the welding consumables: Selecting the correct filler metals and gases will optimize both cost and productivity. Don't rely on “but that's how we’ve always done it”. A switch to a different filler metal may save money and produce better quality welds.

6. Weld inspection: The inspector is there to help avoid defects. 

                                                                                                                                                                                                                                                                  Fig.8. Welder PPE                 

9. Start from Design

The design engineers have to design sound economic welds with proper parts tolerances to produce good material fit up of welded components. Quality control isn’t only about

inspecting products after they are produced. In fact, it often begins at the very first step in the manufacturing process–ensuring that design engineers have all the information

they need to properly design a part, and making sure they are properly trained on any software they use while creating the design.

Joint Geometries

Runoff tabs are used to completely fill out the groove and achieve a uniform weld. Runoff tabs provide excellent method for starting and stopping all 

welding because all defects normally associated with starts and stops are located in areas that later will be discarded. A typical runoff tab is shown in

Figure 9.

Selection of material for runoff tabs is important. The composition of the tabs should not adversely affect the properties of the weld metal [9].

Fig.9. Run Off Tab                         

10. Weld Defect Prevention

Welding is Special

All of us in the welding industry know that welding is special. Welding as a joining process, however, receives special consideration in the more formal way. In terms of quality

management, welding is indeed considered to be a special process. After-the-fact testing and inspection cannot ensure a quality weldment, the desired quality must be as a

result of a continuous stream of properly executed steps from material selection in the beginning to inspection of the finished products at the end [10].                                                                         

Standards provide the basis for conformity and product assurance and ensure the safety and health of the manufacturer and end users. Any welding code or standard is a

minimum requirement. While codes maybe the minimum acceptable standard, they do give us a starting place.

To claim that a weld is high quality, it should exceed the standard outlined in the code in some measurable way.

If a code says: undercut should not exceed 0.8mm. A quality weld should have ‘No undercut’.

If a code says: some porosity allowed. A quality weld should have ‘No porosity’.

To consistently achieve high quality results, one should aim for a level that goes beyond the minimum [12].

Use work instructions to enhance weld quality. This is a document that follows the job order throughout the production process. It includes material acquisition, the required

number of parts, processes involved, along with inspection stops and details at each step. Including a signoff with a date and time stamp at each step helps production flow

analysis through the manufacturing process [13].

Inspection Personnel

Welding inspection is not a simple task. The use of low cost inspection personnel may not result in a bargain. If the individuals being employed are not properly trained or

experienced, there is an increased possibility that the inspection being performed will not be done properly. This could lead to unacceptable evaluation of the component

being inspected. As a result, acceptable welds could be rejected or unacceptable ones approved. In either case, the possible impact on the cost could be phenomenal [14].

Integrity is one of the most important characteristics inspectors can have in the welding industries. In many cases, lives literally depend on it. Unfortunately, many inspectors

are hesitant to raise the red flag when they see quality issues. That hesitant can come from many angles such as production halts, minds coverage, non conformances,

blown the budget and people are pointing fingers at the inspector [11].

Professional Attitude

In order to provide consistent, uniform quality determinations, inspection personnel should base their decision on recognized standards and not what they personally feel

is good or bad. Any inspector having the attitude that he’s not doing his job properly unless he finds something to reject is not helping the situation. In fact, in many cases,

such an attitude does nothing to improve the quality of the product.

Performance of unnecessary repairs can often introduce defects or otherwise render the part unfit for service. Even if this is not the case, needless rejections will at least

add cost to the product. There have even been cases where an unprofessional inspection job has resulted in excessive costs to the degree that companies have been put

out of business. That obviously, is an extreme, but it has occurred [14].

Field Welding

Field welding can cause some problems, but they are not too serious as long as you maintain control over the welders and you insist that qualified

personnel be employed to perform nondestructive testing of the welds [15]. Take care when welding in the wind. The productivity of steel construction

in the open is greatly increased if gas shielded semi-automatic processes can be used. These processes are regularly used in shop fabrication, but the

precautions taken to ensure the protective stream of shielding gas is not disrupted in the shop must be different when in the field Fig.10.

The prime concern when welding in the field is maintaining the stability of the protective jet of gas coming from gas nozzle. One means of doing this is to

increase the flow rate of the gas. Protective shields and screens either attached to the welding gun or erected around the weld area should be considered,

although they may be too bulky or awkward to construct [16]. Also remember that you learn through mistakes. There is no shame in grinding out bad welds.

In fact, professional welders create perfect welds by recognizing imperfections, grinding them out and rewelding.

Fig.10. Field Welding, Wind Shielding.          

Visual Examination

Anyone who thinks that an effective job of visual examination can result from looking only at the finished product is gravely mistaken. It has been proven that the performance

of effective visual examination before, during and after welding will reveal 80 - 90% of those weld discontinuities that would be detected later by some more expensive and

sophisticated nondestructive examination method [14].

Acceptance or rejection of weld flaws is based on different factors and to mention a vital few are:

• stresses to which the parts will be subjected during service.

• type of material used

• the temperature & pressure to which the parts will be stressed

• its thickness

• the environment (corrosive or non corrosive)

• safety

• consequences of failure

• cost and acceptability of repair, etc..,

There is no guarantee that a repair weld produces a more sound joint than the first one.

“Misalignment may be reduced by pipe rotation. Use of hydraulic or screw type clamps, hammers, heating and buttering of weld shall not be permitted”.

“Welding of each joint should be a continuous operation. The second pass (hot pass) of pipe welds shall be deposited immediately after the root pass in

order to prevent ‘cold cracking’ in the root area due to shrinkage stresses and a joint restraint”.

“Preheat shall be applied in a gradual and uniform manner and shall be maintained throughout the welding operation. The minimum preheat temperature

shall be established on both sides of the joint preparation for a minimum distance of 75 mm or 3 times the material thickness whichever is greater”.

“Distance between welds shall be measured between adjacent edges of the cap passes” Fig.11

         Fig.11. Distance between welds

There are many people who will tell you that the fillet weld size is simply the leg dimension of the weld. However, that is only the case for convex fillet weld

Fig.12.  

                                      Fig.12. Fillet Weld

For a concave fillet weld, however, dimensional limitation is the throat of the fillet weld [14].

Overlap is discontinuity that can be nearly as a crack. It creates a stress riser which magnifies any applied stress.

Overlap is not acceptable. Welds shall be free from overlap. In an attempt to make a big weld in the 2F (horizontal)  position, the welder’s travel speed was

too slow and gravity made the weld sag and create overlap Fig.13. 

Fig.13 Weld Overlap Fillet

Employ or outsource good professionals with appropriate qualifications and training for welding procedure writing and welding audit at the production. 

11. Non-Destructive Testing                                                                                                                                                                                                                                 

NDT is also known as non-destructive examination or evaluation (NDE). These techniques apply physical principles for the detection of flaws or discontinuities in materials

without impairing their usefulness. There are a number of examination methods or techniques. In the field of welding, five non-destructive tests are widely used: Visual

Testing, Penetrant Testing, Magnetic Testing, Radiographic Testing and Ultrasonic Testing. Each of these techniques has specific advantages and limitations.

Radiographic Testing: 

It is a NDT method that uses invisible, x-ray or gamma ray to examine the interior of materials.

The RT film interpreter:

• shall be capable of distinguishing the type of defects correctly

• to have training and education along with experience 

• to go to the field and visually examine the reject, especially those that may have been questionable

• shall be able to make decisions which imperfections may be tolerated and which should be treated as defects

• must have a knowledge of welding fabrication

Judgement of defects:

• important factor in control in the quality of the product 

• the RT film interpreter must face up to the ethics of the profession.

• get all the facts and give a balanced judgment.

Fig.14.RT Film Interpretation.               

12. Fabrication Procedure

• A quality welding job is impossible without a good fit up

• A double-V has less weld volume than a single-V

• The root face is meant to prevent burn-through

• If a groove angle is too small there is a risk of lack of penetration or lack of side wall fusion

• All welding should be done in the 1G position if possible

• A welder who is working in a comfortable position will produce higher quality welds 

• Preheating is a very effective means of reducing the chances of cracking in welds                                                                                                                                               Fig.15. Structural Workshop

• The practice of welding over paint should be discouraged.

• Welding should be done on the clean metal

• Knowledgeable & qualified personnel needed for welding quality                                                                                                        

• Proper review of client / project specification required. The welder is allowed to make production welds within the range of qualification recorded

  on his welder qualification card & record.

There is no defectless weld

Acceptance level of defects and NDT methods vary depending on code, service, product needs and contract requirements of the same weld. Proper communication

between welder, NDT technician, inspector, welding engineer can reduce/ eliminate defective joints. The welder and the supervisor are the heart of any weld quality

and productivity improvement process. This team applies the technology of welding with their management system to achieve planned results. Welding fixtures play

an important role in both locating and positioning parts correctly to produce cost effective and quality weldments.

Take action to supply and make available measurement gauges such as fillet gauges for the welders so they could check and verify their own work. Expect both the

welders and their supervisors where to check the weld sizes daily [5].

A visit to the welding exhibition shows clearly that the development of electronic components, computer technologyand digital communication influences the

development of the welding equipment. A good weld requires clean base metal and good joint preparation.

Conclusion

There are three major conclusions that can be drawn from this work. The first one is: to meet those objectives of the welding industries mentioned in this article, the

industry to:

• attract more people to the field of welding in the workplace and in academia

• train more specialists in the fields related to welding

• make welded fabrications with a concern for the environment

• ensure a safe & helpful working environment for workers [5].

The second conclusion is that wise investments in capital goods and communication between the welding industry and its customers are also believed to be very

effective methods for improving welding’s competitiveness. Likewise, the sharing of our experiences about welding operations within industry will ensure progress

throughout the fabrication, manufacturing and construction industries. Finally, welding depends  greatly on the human factor. But it is very important to remember

that an intelligently designed, properly constructed weldment is the best and lowest cost solution for joining any metal product.

Trained and qualified personnel, good supervision, qualified procedures and non destructive evaluation can overcome any limitations imposed by the wide variety

of factors involved in striving for that perfect weld [17]. A work force that is appropriately educated at all levels will drive a reduction of weld defect rate that leads to

a quality product and a technology revolution in welding for our country.

Acknowledgement

This article has been written with the assistance of S. Karthikeyan, Assistant Manager – Welding Engineering, Wheels India Pvt Ltd., (Energy Equipments Parts

Division), Irungattukottai, Sriperumbudur, Tamilnadu. I would like to extend my sincere thanks to everyone involved.

References

1. Welding forges into the future – Andrew Cullision and Mary Ruth Johnson

2. AWS Inspection Trends – August 2023, Page 20

3. AWS Inspection Trends - Summer 1998, Page 26, 29

4. Total Welding Management - J.R.Barckhoff, Page 167

5. Vision for welding industry – AWS, Page 21 to 25

6. Total Welding Management – J.R.Barckhoff, Page 171

7. A vision for welding – David J.Landon – AWS WJ December 2015, Page 6

8. Total Welding Management – J.R.Barckhoff, Page 38,146,158,161,162

9. SMAW best practices – AWS WJ June 2009, Page 48, Fig 2

10. Welding is special – Jeffrey R.Hufsey – AWS WJ 1997, Page 12

11. Integrity in the face of adversity– Curt Green – AWS WJ February 2024, Page 3

12. Aim higher! – Seth Davis - Inspection Trends February 2025, Page 22

13. 3 simple steps to enhance weld quality – Jim Mosman – The WELDER Nov/Dec 2029, Page 58

14. What are the causes of and solutions to weld quality conflicts? - R.L..Holdren – AWS WJ August 1993, Page 59, 60, 64

15. Blockbuster events in welding’s long history – Bob Irving – AWS WJ June 1999, Page 64

16. Take care when welding in the wind – Metal working press notes – Andrew Cullision – AWS WJ June 1994, Page 14

17. Imagine your life without it – Marty Baker, Editor – HIWT

18. Is there sufficient emphasis on weld quality in most welding operations? By Howard Woodward – AWS WJ March 1994, Page 20, 21

19. Eight steps to a successful weld – Don Bobyk, Bob Hetzendorfer – AWS WJ December 1999, Page 41,42,43